JP2005156640A - Connecting mechanism of grand piano - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting mechanism of a grand piano with which rich sound volume and excellent sound quality can be stably obtained by suppressing local strain of a soundboard caused when the tension of strings operates on the soundboard. <P>SOLUTION: The connecting mechanism 1 of the grand piano for connecting a plurality of columns 7 to a frame 11 has a column abutting part 4 that fronts of the plurality of columns 7 abut, a column fitting part 3 which is screwed to front ends of the plurality of columns 7, and a connection part 5 which extends forward from the column fitting part 3 and has a bolt screw-together part 5a at its front end, and is equipped with a connection member 2 which is provided in a nonconnection state to a back beam 8, an intermediate beam 9, and a rib 10 and a connecting bolt 6 which is screwed in a free inward/outward movable state in the bolt screw-together part 5a of the connection member 2 and abuts against the frame 11 to connect the plurality columns 7 to the frame 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a connecting mechanism for a grand piano used to connect a column and a frame in order to support tension of a string.

  As a conventional connecting mechanism of this type of grand piano, for example, one disclosed in Patent Document 1 is known. As shown in FIGS. 5 and 6, the connecting mechanism 51 is provided on the front surface of the collector plate 52 having a mounting plate-like portion 52 a and a connecting rod portion 52 b formed on the upper surface thereof, and the intermediate rod 57 and the driving wheel 58. A connection fitting 53 provided, a bolt 54 for connecting the collector 52 and the connection fitting 53, and the like are provided. A plurality of holes 52c for screwing are formed in the attachment plate-like portion 52a. The connecting rod portion 52b protrudes forward from the central portion of the upper surface of the mounting plate-like portion 52a, and a screw hole 52d is formed at the front end portion thereof.

  The support column 55 is composed of four wooden support columns 55. The rear end portions of the support columns 55 are fixed at different positions on the pile (not shown), and the front end portions are concentrated on the back 56, and the front surface thereof. Is in contact with the back surface of the back 56. In the state where the front end portion of the connecting rod 52b penetrates the driving device 58 provided in the front surface of the upper surface of the intermediate rod 57, the collector 52 is supported by a plurality of screws 59 passed through the holes 52c of the mounting plate-like portion 52a. , And are fixed to the upper surfaces of the back 56 and the middle 57. The connection fitting 53 is formed in an inverted T shape, and is fixed to the front surface of the intermediate collar 57 by screws 60 and 60 that are passed through a plurality of holes 53b formed in the lower half portion thereof. In addition, a bolt through hole 53a is formed in the upper half of the connecting metal 53, and a bolt 54 is passed through the bolt through hole 53a. Then, by screwing the bolt 54 into the screw hole 52d of the connecting rod portion 52b via the washer 61 and the nut 62, the upper half of the connecting metal 53 is driven around the nut 62 and between the 58 and the connecting rod portion 52b. While being clamped, the bolt 54 is fixed in a state where the head of the bolt 54 is strongly pressed against the jaw 63a of the frame 63. As a result, the frame 63, the support column 55, the back rod 56, the center rod 57, and the driving wheel 58 are firmly connected to each other via the collector 52, the connection fitting 53, and the like.

  As described above, when the frame 63 is connected to the support column 55 via the connection mechanism 51, a large tension of strings (not shown) acting on the frame 63 causes the frame 63, the support column 55, and the back 56. It is fully supported by collaboration with the middle rod 57 and the like.

  However, in the conventional coupling mechanism 51, as described above, the frame 63 is firmly fixed not only to the support column 55 but also to the back rod 56, the middle rod 57, and the driving device 58 via the collector 52 and the coupling metal 53. It is connected. For this reason, a large tension of the string is transmitted from the frame 63 to the back rod 56, the middle rod 57 and the driving wheel 58. A sound board (not shown) is directly bonded to the driving wheel 58. Therefore, the large tension of the strings as described above also acts on the soundboard through the driving 58, and as a result, the soundboard is distorted.

  FIG. 7 shows the result of measuring the distortion of the soundboard in a state where the string is stretched in a conventional grand piano in order to confirm the influence of the tension of the string on the soundboard. As shown in the figure, the distortion of the soundboard is the largest in the area A at the front center of the soundboard, and the area B surrounding it is the next largest. This is because the tension of the string acts on the portion where the coupling mechanism 51 is provided.

  As described above, when a large strain is applied to the driving force 58 and a local distortion occurs in the soundboard, the free vibration of the soundboard is inhibited and the sound is less likely to sound, so that the sound volume is lowered. . In addition, sound quality is deteriorated due to lack of sound expansion and tension.

  The present invention has been made to solve such a problem, and suppresses local distortion of the soundboard due to the tension of the strings acting on the soundboard. An object of the present invention is to provide a grand piano coupling mechanism capable of stably obtaining sound quality.

JP-A-11-212542

  In order to achieve this object, the invention according to claim 1 includes a back, a center rod, and a strut arranged in front of a plurality of support columns extending in the front-rear direction and sequentially connected to each other, and is stretched on a frame. In the grand piano provided with a soundboard that vibrates as the string is struck on the upper surface of the driving, it is a connecting mechanism of the grand piano for connecting the plurality of columns and the frame, and the front surfaces of the columns are A strut abutting portion that abuts, a strut attaching portion screwed to the front end portion of the plurality of struts, and a connecting portion extending forward from the strut attaching portion and having a bolt screw portion formed at the front end portion. At the same time, the connecting member provided in a non-connected state with respect to the back, the center and the driving force, and the bolt screwed portion of the connecting member are screwed so as to be able to advance and retreat, and a plurality of columns and the frame are brought into contact with the frame Connect Characterized in that it comprises a connecting bolt, a.

  According to this configuration, the column support portions of the connection member are screwed to the plurality of columns, and the connection bolts screwed into the bolt screwing portions of the connection member abut on the frame, whereby the plurality of columns and the frame are connected. Are connected to each other. Therefore, the tension of the string stretched on the frame can be sufficiently supported by the cooperation of the frame and the plurality of support columns coupled to the frame via the coupling mechanism. Furthermore, since the connecting member is provided in a non-connected state with respect to the back, middle and driving, the string tension acting on the frame is prevented from acting on the soundboard through the driving. It is possible to suppress the local distortion of the soundboard. As a result, rich sound volume and good sound quality can be stably obtained by maintaining the free vibration of the soundboard well.

  The invention according to claim 2 is the grand piano connecting mechanism according to claim 1, wherein the driving has a through hole extending in the front-rear direction, and the connecting portion of the connecting member is non-contact with the driving. In this state, it is passed through the through hole and extends forward.

  According to this configuration, since the connecting portion of the connecting member is passed through the through-hole in a non-contact state with respect to driving, the tension of the string is directly transmitted to the driving through the connecting mechanism. Can be reliably prevented, and the distortion of the soundboard caused thereby can be suppressed.

  According to a third aspect of the present invention, in the grand piano coupling mechanism according to the first or second aspect, the coupling member is spaced in the front-rear direction between the strut abutting portion of the coupling member and the inner wall. It is arranged.

  According to this configuration, since the connecting member is disposed with a space in the front-rear direction between the column abutting portion and the back, the tension of the string is transmitted from the plurality of columns via the connection mechanism. Can be reliably prevented from being transmitted to the back. As a result, it is possible to reliably prevent the tension of the string from being transmitted to the inner ring, and the intermediate hook and the hammer that are sequentially connected thereto, thereby suppressing distortion of the soundboard.

  The invention according to claim 4 is the grand piano connecting mechanism according to any one of claims 1 to 3, wherein the connecting portion of the connecting member is composed of a plurality of connecting portions.

  According to this structure, since the connection part of a connection member is comprised with a some connection part, it can support with sufficient balance, disperse | distributing the tension | tensile_strength of a string to a some support | pillar.

  The invention according to claim 5 is the grand piano connection mechanism according to any one of claims 1 to 4, wherein the column attachment portion of the connection member is screwed to the upper surface of the plurality of columns. .

  According to this configuration, since the column attachment portions of the connection member are screwed to the upper surfaces of the plurality of columns, the connection member can be easily attached to the column only by tightening the screws from above.

It is the elements on larger scale which show the state which connected the support | pillar and the flame | frame with the connection mechanism of the grand piano by embodiment of this invention. FIG. 2 is a side view of the state corresponding to FIG. 1 with a soundboard attached and unloaded. It is the top view which attached the connection mechanism of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a partial enlarged plan view which shows the state which connected the flame | frame, the support | pillar, etc. with the connection mechanism of the conventional grand piano. FIG. 6 is a side view corresponding to FIG. 5. It is a figure which shows an example of distortion distribution of the soundboard at the time of using the conventional connection mechanism.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following explanation, it is assumed that the front side (lower side in FIG. 3) of the grand piano viewed from the performer is “front” and the rear side (upper side in FIG. 3) is “rear”. To do. First, the configuration of the coupling mechanism 1 will be described with reference to FIGS. As shown in these drawings, the coupling mechanism 1 includes a coupling member 2 and a coupling bolt 6.

  The connecting member 2 is made of a pressed metal such as iron or cast metal, and includes a column attachment portion 3, a column contact portion 4 that extends vertically downward from the front end portion thereof, and a front side of the column attachment portion 3. A plurality (four in this example) of connecting portions 5 are integrally provided.

  The column attachment portion 3 is an elongated plate-like one that extends continuously in the left-right direction between the left and right end portions of the front portion of the pile 13, and has a predetermined width and thickness in the front-rear direction. A plurality of holes 3 a for screwing are formed at predetermined positions of the column attaching portion 3. The column abutting portion 4 is provided over the entire column mounting portion 3 in the left-right direction, has a predetermined thickness in the front-rear direction, and extends downward beyond the column 7 to the vicinity of the shelf board 18. Upper and lower two screw holes 4a for screwing the bolts 17 are formed on the left and right side surfaces of the column contact portion 4. The four connecting portions 5 are provided at predetermined positions spaced apart in the left-right direction. Each connecting portion 5 has a rectangular cross section, and a bolt screwing portion 5a is formed at the front end portion so as to extend in the front-rear direction.

  The column 7 is composed of a plurality of, for example, five wooden columns 7. As shown in FIG. 3, these struts 7 extend in the front-rear direction, and their rear ends are fixed to different positions of the pile 13 having the outline of a grand piano with screws (not shown) or the like. ing. A bolt hole 13a penetrating laterally is formed at a predetermined position of the pile 13 and a bolt 17 is passed through the bolt hole 13a. Further, in the front of the column 7, a back rod 8, a middle rod 9 and a driving wheel 10 are provided. Each of the inner rod 8, the middle rod 9 and the driving wheel 10 is made of wooden square material, and is passed between the left and right end portions of the front portion of the pile 13. The back 8 is disposed at a predetermined interval in the front-rear direction in front of the column 7, and a shelf 18 is attached to the back 8 via a shelf attachment 19. The intermediate hook 9 is connected to the upper front portion of the back rod 8 in a state where the upper surface is flush, and the driving wheel 10 is connected to the upper surface of the intermediate rod 9 in a state where it is placed.

  In the driving device 10, four through holes 10 a that penetrate in the front-rear direction are formed at positions corresponding to the connecting portions 5 of the connecting member 2. Each through hole 10 a is formed in a rectangular shape corresponding to the shape of the connecting portion 5 of the connecting member 2, and has a slightly larger width and height than the connecting portion 5. Further, the front end portion of the soundboard 12 is placed on the upper surface of the driving wheel 10, and the peripheral portion except the front end portion of the soundboard 12 is placed on the pile 13.

  A frame 11 is provided above the soundboard 12. The frame 11 is made of a casting. A large number of tuning pins and hitch pins (both not shown) are driven into the front end portion and the rear end portion of the frame 11, and strings (not shown) are arranged in the front-rear direction between these tuning pins and hitch pins. It is stretched to extend. Further, a piece (not shown) is provided on the top surface of the soundboard 12, and a string is engaged with a piece pin (not shown) of this piece, and a hammer (both not shown) is accompanied by pressing the key. As the string strikes the string, the string vibrates, and the vibration of the string is transmitted to the soundboard 12 to generate a piano sound. In addition, at predetermined positions of the frame 11, four jaw portions 11 a (only one is illustrated) extending downward are provided at positions corresponding to the connecting portions 5 of the connecting member 2.

  The connecting member 2 of the connecting mechanism 1 has an upper surface of each column 7 by a plurality of screws 14 passed through the holes 3a of the column mounting part 3 in a state where the back surface of the column contact unit 4 is in contact with the front surface of the column 7. It is fixed to. In this state, as shown in FIG. 4, the connecting portion 5 of the connecting member 2 is passed between the inner surface of the through-hole 10 a of the driving 10 in a non-contact state with a gap G 1. Projects forward. Further, a gap G <b> 2 (see FIG. 2) is formed in the front-rear direction between the column abutting portion 4 of the connecting member 2 and the back 8.

  Further, the connecting bolt 6 is screwed into the bolt screwing portion 5a of each connecting portion 5 via the washer 15 and the lock nut 16 and turned to the frame 11 side, whereby the connecting bolt 6 is attached to the jaw portion 11a of the frame 11. Abutting in a strongly pressed state. As a result, the frame 11 and the support column 7 are firmly connected to each other via the connection mechanism 1. The lock nut 16 is tightened with respect to the connecting portion 5 after the connecting bolt 6 is brought into contact with the jaw portion 11a of the frame 11, thereby preventing the connecting bolt 6 from loosening. Further, the connecting member 2 of the connecting mechanism 1 is fixed to the pile 13 by screwing a plurality of bolts 17 passed through the bolt holes 13 a of the pile 13 into the screw holes 4 a of the column contact portion 4. The connection member 2 is fixed to the pile 13 after a string is stretched on the frame 11. This is because, if the connecting member 2 is fixed before stringing, stress is generated in the soundboard 12 due to the tension of the string to be tensioned thereafter, and excessive distortion may occur.

  As described above, according to this embodiment, the column mounting portion 3 of the connecting member 2 is screwed to the column 7 and the connecting bolt 6 screwed into the bolt screwing portion 5 a of the connecting member 2 is attached to the frame 11. By abutting, the support column 7 and the frame 11 are connected to each other. Therefore, the tension of the string stretched on the frame 11 can be sufficiently supported by the cooperation of the frame 11 and the five struts 7 connected to the frame 11 via the connecting mechanism 1.

  Further, since the connecting portion 5 of the connecting member 2 is passed through the through hole 10a formed in the driving 10 in a non-contact state, the tension of the string is directly transmitted to the driving 10 via the connecting mechanism 1. Can be surely prevented. Moreover, since the support | pillar contact part 4 of the connection member 2 is arrange | positioned in the state which left | separated the space | interval G2 in the front-back direction between the back part 8, the tension | tensile_strength of a string is via the connection mechanism 1 from the support | pillar 7. Transmission to the back 8 can be reliably prevented. Thereby, it is possible to reliably prevent the tension of the string from being transmitted to the driving wheel 10 through the back rod 8 and the intermediate rod 9 connected thereto. As described above, it is possible to prevent the tension of the string from acting on the soundboard 12 through the driving 10 and to thereby suppress the distortion of the soundboard 12. As a result, by maintaining the free vibration of the soundboard 12 well, a rich sound volume and good sound quality can be stably obtained.

  Furthermore, since the connecting portion 5 of the connecting member 2 is composed of a plurality of connecting portions 5, the string tension can be supported in a well-balanced manner while being distributed to the five struts 7. Moreover, since the support | pillar attaching part 3 of the connection member 2 is screwed to the upper surface of the support | pillar 7, the connection member 2 can be easily attached to the support | pillar 7 only by tightening the some screw | thread 14 from upper direction.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in this embodiment, although the connection part 5 of the connection member 2 is comprised with the some connection part 5, you may comprise the connection part 5 with a single thing like the past. In that case, the through hole 10 a of the driving device 10, the jaw portion 11 a of the frame 11, and the connecting bolt 6 are provided so as to correspond to the connecting portion 5. Moreover, in embodiment, although the support | pillar attaching part 3, the support | pillar contact part 4, and the connection part 5 of the connection member 2 are integrally formed with iron, casting, etc., the several member which comprises these each part, You may form by connecting with each other by welding, screwing, etc. after producing. In addition, it is possible to appropriately change details within the scope of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Connection mechanism 2 Connection member 3 Support | pillar attachment part 4 Support | pillar contact part 5 Connection part 5a Bolt screw part 6 Connection bolt 7 Support column 8 Back 9 Middle shaft 10 Driving 10a Through-hole 11 Frame 12 Sound board G1 Connection part and penetration G2 Distance between the inner surface of the hole G2 Distance between the strut abutment and the back

Claims (5)

A soundboard which is arranged in front of a plurality of struts extending in the front-rear direction and which is connected in order to each other, has a back, a middle, and a striking, and vibrates with the striking of the string stretched on the frame. A grand piano provided on the top surface of the grand piano for connecting the plurality of columns and the frame,
A strut abutting portion with which the front surfaces of the plurality of struts abut,
A column attachment part screwed to the front end of the plurality of columns;
And a connecting portion having a bolt threaded portion formed at the front end portion and extending forward from the column mounting portion, and provided in a non-connected state with respect to the back rod, the intermediate rod and the driving force. A connecting member;
A connecting bolt that is screwed into the bolt threaded portion of the connecting member so as to freely advance and retract, and connects the plurality of columns and the frame by contacting the frame;
A connecting mechanism for a grand piano, comprising:   The driving has a through hole extending in the front-rear direction, and the connecting portion of the connecting member is passed through the through hole in a non-contact state with respect to the driving and extends forward. The connecting mechanism of the grand piano according to claim 1.   The ground according to claim 1 or 2, wherein the connecting member is disposed in a state of being spaced apart in the front-rear direction between the strut abutting portion of the connecting member and the inner wall. Piano connection mechanism.   The grand piano connection mechanism according to any one of claims 1 to 3, wherein the connection portion of the connection member includes a plurality of connection portions. The grand piano connection mechanism according to any one of claims 1 to 4, wherein the column attachment portion of the connection member is screwed to an upper surface of the plurality of columns.

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